In the known pneumatic blower conveying systems, such as is described in U.S. Pat. Nos. 2,688,517 and 2,688,518, difficulty is encountered with periodic clogging of the filters which must be employed to dissipate the airstream once it has been returned to the storage bin, because the separation of the flour from the conveying airstream has not heretofore been as effective as is desirable. Such systems must be shut down at regular intervals so that the filters can be removed, cleaned, and replaced or in some installations so that filters can be subjected to reverse air cleaning action. Further, the provision of such filters in effect opens the storage bin to dust and possible infestation by insects.
U.S. Pat. No. 3,030,153 represents an improvement over the aforementioned known devices in that the device enables a pneumatic conveying of product from one location to another without the use of filters. This system, however, is not entirely satisfactory due to the inability of the system to accommodate materials of differing granular sizes. In other words, a different vacuum receiver device would need to be utilized in situations where product having different granular sizes was utilized in order to prevent the flow of product through the exhaust line toward the exhaust blower. Accordingly, a need has arisen for enabling a single vacuum receiver to be utilized in the handling of a multitude of different dry, powdered and granular products.
Accordingly, it is an object of this invention to provide a vacuum receiver in which there are no filters in the fluid circuit for the purpose of releasing the product from the airstream as the airstream is exhausted from the system via an exhaust blower.
It is a further object of this invention to provide a vacuum receiver, as aforesaid, which has the ability to accommodate differing materials under wholly separate operating conditions and without necessitating a replacement of any of the components in the system.
It is a further object of the invention to provide a vacuum receiver, as aforesaid, wherein the adjustment required to accommodate product of different granular size can be made easily and with a minimum of difficulty.
It is a further object of this invention to provide a vacuum receiver, as aforesaid, wherein the vacuum receiver is adapted to be mounted on existing hopper constructions in the field.